Liquid for treating motion-picture film



1950 B. GRUTER 2,517,201

LIQUID FOR TREATING MOTION-PICTURE FILM Filed March 1, 1945 2 Sheets-Sheet l Aug. 1, 1950 B. GRUTER LIQUID FOR TREATING MOTiON-PICTURE FILM Filed March 1, 1945 2 Sheets-Sheet 2 Patented Aug. 1, 1950 UNITED STATES PATENT OFFICE LIQUID FOR TREAiI ZI Z LOTION-P CTUR V Bernhard Griiter, Lucerne, Switzerland, assignor to. Klar-Film A- G., Zurich, Switzerland Application March 1 1945, Serial No. 580,315

3 Claims. (01. 106--271) The present invention relates to a motion picture apparatus combined with sound producer and especially to a new and improved method to make used picture film bands more translucent after the same has become dull and scratched after much use. This operation is performed shortly before the use while the film band passes the gate of a film projector. The invention relates moreover to a device to automatically perform the said operation while theimages of the film band are being. projected. The invention is applicable also to sound or talking films projectors.

The object of the invention is to improve the reproduction of sound and images and I attain the: object by moistening the film band shortly in advance of the gate of the projector by which the projection of the images is performed. Themoistening is eflected by means of a non-ignitable fluid having the same or nearly the same refraction of light as the material of which the film band consists. A liquid adapted. for the 'said purpose is for instance a halogenised hydrocarbon and more particularly carbon tetrachloride.

Carbon tetrachloride like all the halogenised hydrocarbons would make the film band in a very short time brittle and of no further use. To obviate this drawback, natural wax for instance beeswax or carnauba, wax is added to the halogenised hydrocarbon. This addition keeps the film band pliable.

Halogenated hydrocarbons have a pungent odor. It is therefor advisable to add some perfume, for instance eucalyptol or eucalyptus oil or gum. The addition of the last said means and especially of eucalyptol have moreover a very marked eflect on the improving action of the tetrachloride. Other means for instance lavender oil or pine needle oil may be used to cover the odor of the carbon tetrachloride.

It has been found that good results are obtained by the addition of .10 per cent of wax and .50 per cent of perfume.

Example-0.8 gram of Wax, heated in a hot water bath are dissolved in 100 grams carbon tetrachloride and after cooling further 800 grams of carbon tetrachloride and 5 grams eucalyptol are added. The resulting liquid is passed on to cushions of felt or the like by which the liquid is evenly distributed on the film band.

It has been found by experience that a film band treated as described may be used for about 3,000 performances While a non-treated film band is generally used only 400 to 500 times. The sound films may be reproduced free of any acture film are free of any colored stripes and the like.

In the accompanying. drawing two examples of a device to treat thefilm according to the process described are shown in a diagrammatical manner;

Figs. 1 and 2 are side elevations of a device destined for narrowfilm bands. T l

Fig. 3 shows the means for applying the fluid to the film band insection and on alarger scale.

Fig. 4 is a section taken on line 4-4 of Fig. 3.

Fig. 5 illustrates ina diagrammatical the run of a film band of standard width through the projecting apparatus. 1 l

Fig. 6 shows the deviceuto apply the fluid on to the film band, the broken lines illustrate the lid in its opened position.

Figs. '7, 8 and!) are sections taken on the lines l--l, 8-8 and 9-0 of Figs. 5 and 6 on a larger scale. l l t On a base plate a standard 2 is arranged carrying at its upper end a container 3 for the fluid by means of which the film band is cleaned. On the standard 2 a hollow arm 5 is adjustably mounted by means of a clamp-4 which may be closed by screw 5. The arm 5 may be adjusted lengthwise and-may be turned about its axis. The tubular arm 5 is provided at its free end with a ball shaped head i. On the latter a casing 8 is adjustably mounted. In the casing 8 two cushions 9, IQ of fluid adsorbing material for instance porous rubber are arranged. In a Wall of the casing Ill four screw threaded bores H are arranged. In two or said bores II on both sides of the cushions 9, ill a guideroller it is mounted by apin (Fig. 3 Afilm band l2; which is to be cleaned and which has to pass between the cushions 9, 10 runs over the said rollers [8. The cushion I0 is arranged on a holder [4 hinged to the casing 8 by a, pin !3. On said pin a torsional spring I3 is arranged which tends to press the cushion it against the cushion 9: By pressing on a handle l5 the cushion it may be passed downwards and the film band l2 may be positioned between said cushions 9, l0 and on the rollers l8. To retain the cushions 0, l0 apart a springy stop It is fastened to the wall of easing 8. The free end of the stop It may pass over a nose I! on the lid it after the latter has been pressed down. By means of a button M) (Fig. 4) the stop It may be brought out of engagement with said nose I! freeing thereby the lid M which is brought to bear on the film hand 12 and on cushion 9 by the expanding spring I3. Between the lid l4 and the cushion I8 leaf springs l5 are arranged which allow the cushion I to bear with its full upper face on the film band l2 pressing same on to cushion. The liquid to clean and to improve the transparency of the film band l2 which is stored in the receptacle 3 passes by a tube 28 and pipe 5 through bore 2| to the cushion 9. The flow of the liquid can be controlled by a hand operated valve 24. A small tube 22 arranged in the container 3 opens into atmosphere by a bore 23 in the valve body 24.

The new device may be used in connection with many types of film projectors, the casing 8 may be placed in any appropriate position. The film band l2 passes from the spool 26 through the casing 8 and over guide rollers" through the window D of the projecting apparatus 25 and passes on to the spool 21. The liquid from the container 3 under a small head fills both the cushions 9, Ill. The film band I2 is moistened and cleaned. The vapors escaping are dangerous to the health of the operators, they are removed below the gate by means of a nozzle 80 connected by a tube 8| with a'sucking-ofi ventilator ,82 and therewith with a tube leading to a chimney or into atmosphere. The casing 8 extinguishes moreover the film band [2 should the same by accident catch fire.

The device shown in Figs. 1 to 4 might be well used for narrow film bands l2, while the device shown in Figs. 5 to 9 is adapted to clean and to clear wider film bands l2.

The device 8 to moisten the film band I2, is connected by a tube 58 to a liquid container 3| arranged at the wall 32 adjacent the spool 26, 33. In the tube 58 a valve 34 is arranged to control the flow of liquid to the device 8. The latter comprises two cushions 40, 4| of loose felt through which liquid may pass. The film band l2 which passes on to the window D is led over the guide rollers 42, 43, 44 rotatably mounted in the casing 45, it passes between the cushions 40, 4| to a roller 46 leaving the casing 45 over a roller 41. The cushion 40 is held fast in the casing 45 by needles 50 fixed to the said casing. The cushion 4| rests on blade springs 5| and held near the film band l2. To press said cushion 4| on to the film band a roller 55 is rotatably mounted in bearings 54 of the lid 53. If the lid 53 is in closed position, the roller 55 presses the blade springs 58 on to the back of the cushion 4| and presses the latter on to the film band 12. The cushion 4| resting on the said springs 56 adapts itself and presses with its full upper face on the film band l2. Liquid is fed by the tube 58 from the container 3| into channels 51 at the back wall of the cushion 40. To keep the film band. I2 taut, the

4 roller 43 is mounted on a lever 60 adjustably mounted on the casing 45. Near the gate D the nozzle is arranged by which vapors are drawn-off and passes on to a chimney as described with reference to Figs. 1 to 4.

What I wish to secure by United States Letters Patent is:

1. A liquid for rendering scratches on motion picture film temporarily invisible, consisting of a non-ignitable halogenized hydrocarbon having substantially the same index of refraction as the film and having a wax in the amount of .10 per cent by weight dissolved therein.

2. A liquid for rendering scratches on motion picture film temporarily invisible, consisting of carbon tetrachloride and having a wax in the amount of .10 per cent by weight dissolved therein.

3. A liquid for rendering scratches on motion picture film temporarily invisible, consisting of carbon tetrachloride having a wax in an amount of .10 per cent by weight dissolved therein and containing an amount of an odorous oil suflicient to overcome the objectionable odor of said carbon tetrachloride.

BERNHARD GRUTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,139,679 Hochstetter May 18, 1915 1,139,682 Hochstetter May 18, 1915 1,208,664 Russak et a1. Dec. 12, 1916 1,535,999 Harrington Apr. 28, 1925 1,580,180 VanDerhoef Apr. 13, 1926 1,997,269 Stewart Apr. 9, 1935 2,117,828 Soman May 17, 1938 2,150,757 Bodine Mar. 14, 1039 2,259,009 Talbot Oct. 14, 1941 FOREIGN PATENTS Number Country Date 234,264 Germany May 5, 1911 25,771 Great Britain of 1909 2,326 Great Britain Jan. 28, 1914 388,369 Great Britain Feb. 10, 1933 OTHER REFERENCES Finnimore, The Essential Oils, 1926, pages 566-567.

Condensed Chemical Dictionary, 3rd ed., 1942, pages 284-285.

Chemical Formulary, Bennett, vol. VI, 1943, page 394. 

1. A LIQUID FOR RENDERING SCRATCHES ON MOTION PICTURE FILM TEMPORARILY INVISIBLE, CONSISTING OF A NON-IGNITABLE HALOGENIZED HYDROCARBON HAVING SUBSTANTIALLY THE SAME INDEX OF REFRACTION AS THE FILM AND HAVING A WAX IN THE AMOUNT OF .10 PER CENT BY WEIGHT DISSOLVED THEREIN. 